Telegraph signal enciphering mechanism



1945- w. y. LANG ET AL 2,406,020

TELEGRAPH SIGNAL ENCIPHERING MECHANISM Filed July 1, 1942 2 Sheets-Sheet 1 FIG.

KEYBOARD PERFORATOR KEYBOARD HERFORATOR T w 1. LANG WVEMORS'E Ir WATSON ATTORNEY Aug. 20, 1946.

W. Y. LANG ETAL TELEGRAPH SIGNAL ENCI-PHERING MECHANISM Filed July 1, 1942 2 Sheets-Sheet 2 W. K LANG INVENTORSZEE WATSON W A T7'0RNE V Patented Aug. 20, 1946 UNIT STS PATENT arcane Fries TELEGRAPH SIGNAL ENCIPHERING MECHANISM Application July 1, 1942, Serial No. 449,266

Claims.

This invention relates to enciphering systems for permutation code telegraph signals. More particularly, thi invention relates to the full mechanical preparation of random key tape for use in enciphering and deciphering such signals.

There are presently available a number of devices for preparing ciphering key tapes. The present invention has the advantage of employing apparatus used in well-known telegraph systems. No special apparatus is required. The characters in key tapes produced by this method have been found by actual count of frequency and sequence to closely approach perfect random. Further, the device is a full mechanical arrangement. It requires no manual manipulation and a minimum of adjustment.

It is an object of this invention to provide a full mechanical device employing telegraph system apparatus for producing random key tape for an automatic enciphering and deciphering system.

The invention may be understood from the following description when read with reference to the associated drawings in which:

Fig. 1 shows two transmitting distributors to each of which signal elements are supplied from two different sources and in which the signal elements supplied from the two sources are combined so that the output from the distributors is relatively random. One source of signal elemen supply for each distributor, as shown is an individual punched tape which is produced, as indicated, in an individual keyboard perforator associated with each distributor. This tape is preferably one containing all possible combinations in the code an equal number of times but with the characters punched in random sequence. The tapes in the two transmitters may be in the forms of long repeating loops, but if so they should be of different length. I'he second source of signal element supply for each distributor is a single vibrating relay which serve both distributors. The trains of signal elements as transmitted by each of the two distributors represent the combination of the signal elements impressed on the distributor by the hey tape and the signal elements impressed on the distributor by the vibrating relay. The random signals resulting from the combination of these two signals in each distributor are transmitted through an individual output circuit from each distributor; and

Fig. 2 shows two polar relays each of which receives and repeats the signal supplied by each of the two distributors of Fig. 1. It shows also a five-bank selector in which the signal elements repeated by the two relays are combined and which is arranged to be stepped at interval to scramble the output from the two polar relays in different manners in response to the production of a specific symbol in the output of the scrambling mechanism. It shows also a distributor in Switches E5, E5, and 25 keys such as 3 and 4. As the keys are depressed, tapes 5 and 5 are perforated in a Well-known manner. When suificient tape has been punched, switch controls 1 and 8 are lowered closing contacts 9 and l El. When contacts 9 and i5 are closed, a circuit is established which may be traced from battery H through the winding of magnet 12, winding of magnet 13, contact 9, switch Hi, contact ii], and switch [5, to ground i5. Magnets l2 and I3 attract their respective armatures ii and ES. The armatures are rotated in a clockwise direction around fixed pins 19 and 25, respectively. Th right-hand end of each armature withdrawn from its position against shoulders 2| and 22 of cams 23 and 24. Power is supplied when switches 25 and 26 are closed from source 2? to motors 28 and 29 which rotate shafts 3D and 5!. Shaft and 3| are coupled through clutches 32 and 33 to the driven shafts 34 and 35. The driven shafts are coupled through worms 36 3'! and gears 38 and 39 to the distributor shafts and 4!. When the right-hand end of the armatures H and I8 are withdrawn from engagement with the shoulders 2| and 22, shafts 4E! and 4! are rotated driving the rotary arms 42 and d3 of the distributors 44 and 45.

Depending upon whether a corresponding position in tapes 5 and 'e is punched or unpunched, armatures 45, M, 48, as and associated with tape 5 and armatures 5|, 52, 53, 54 and 55 associated with tape 5 will be in engagement with their respective upper contacts 55, 51, 58, 59, 55, 6t, 52, 63, 55 and or their respective lower contacts 55, 5'5, 58, 59, It, H, l2, 13, M and E5. Each of the armatures 45 to 55 which is in engagement with its upper contact will supply positive battery from source 15 to a particular segment of the group numbered l to 5 on the outer ring of distributor 45 or 55. Each of armatures 45 to 55 which is in engagement with its lower contact will supply negative battery from source i! to a particular segment of the group numbered l to 5 on the outer ring of distributor M or 45. It is pointed out that armatures 4-6 to 55 are connected to segments I to 5 of distributor 45 and that armetures 5| to 55 are connected to segments I to 5 of distributor 44. driven from a sourc of 20-cycle current 79 between its contacts and BI by the efiect of current flowing through its left-hand winding from the ZO-cycle source. When the armature of relay i8 engages its upper contact, a circuit may be traced from positive battery 16 through contact 8| and the armature of relay 18 to parallel The armature of relay is is,

terminals 194a, I95a, [98a and 191a.

branches. The upper branch extends to what are normally the stop segment and the start segment The lower branch extends to what are normally the stop and start segments of distributor 44 which are connected in parallel. When the arma ture of relay 18 is in engagement with its lower contact 89, a circuit may be traced from negative battery 11 through contact 89 and the armature of relay 18 to the same segments of the two distributors.

As long as there is suflicient slack in tapes and 8 contacts 9 and I9 will remain closed. Magnets I2 and I3 will remain energized. Rotary arms 42 and 43 will continue to rotate. As brush 82 sweeps over each segment of distributor 45 positive or negative battery depending upon which is connected to the segment at the instant will be conducted through brush 83 to solid ring 88. Correspondingly, positive or negative battery momentarily on the segments of distributor 44 will be connected. through brushes 84 and 85 to solid continuous ring 81. From the solid ring 88, conductor 88 extends to the top winding of relay 89 and the circuit extends through junction point 99 to the mid-point 9| of t e potentiometer comprised of the circuit which extends from ground to positive battery 92, resistance 93, resistance 94 and negative battery 95 to ground. Similarly, conductor 98 extends from the solid ring 81 of distributor 44 through the bottom winding of relay!" to the mid-point SI of the potentiometer. 7

When negative battery is applied through a segment of either distributor to conductors 88 and 98 the armatures of relays 89 and 91 will be actuated to the left to engage their left-hand contacts 98 and 99, respectively. When positive battery is connected through the distributors to conductors 88 and 98, the armatures of relays 89 and 91 will be actuated to the right to engage their respective contacts I99 and I9I. The circuit through the bottom winding of relay 89 and through the top winding of relay 91 is used to lock the armature in the position which it has assumed. The manner in which this is performed will be described hereinafter.

When the armature of relay 89 is in engagement with contact 98 a circuit may be traced from positive battery through resistance I92, contact 98 and the armature of relay 89 to terminals on the five banks I93, I94, I95, I98 and I91 of the multibank selector I98. Correspondingly, when the armature of relay 91 is in engagement with its left-hand contact 99, a circuit is established from positive battery through resistance I99, contact 99 and the armature of relay 91 to terminals on banks I93 to I91 of selector I98. It may be observed that, in the case of the bottom left-hand row of terminals of selector banks I93 to I91 designated I93a to I91a, the armature of relay 89 is connected to terminal I93a. The armature of relay 91 is' connected to The rotating brushes associated with banks I93 to I91 of selector Hill are connected to five segments, numbered I to 5,of rotary distributor II9. Thus, brush III connects to segment 5, brush II2 connects to segment 4, brush II3 connects to segment 3, brush II4 connects to segment 2 and brush I I5 connects to segment I. The positive battery connected through resistance I92 and contact 98 to the armature of relay 89 will be impressed through terminal I93a of bank I93 and rotary brush III on segment 5 of rotary 4 distributor II9. Positive battery connected through resistance I99, contact 99 and the armature of relay 91 will be impressed through terminal I 9411 and rotary brush H2 on segment 4 of distributor II9. Similarly, this same positive battery will be impressed through terminal Ia and brush II3 on segment 3, through terminal I98a and rotary brush II4 on segment 2 and through terminal H310: and rotary brush M5 on segment I.

When switch I I5 is closed, power is supplied from power source II1 to motor H8, driving shaft II9, clutch I29, shaft I2I, worm I22, gear I23, shaft I24 and rotary arm [25 of distributor I I9. When arm I25 has rotated into the position so that brush I28 engages segment i, positive battery will be connected through brushes I28 and I21, solid continuous ring I28 of distributor H9, conductor I29, resistance I39 and the bottom winding of relay I3I to mid-point I32 of a potentiometer. The potentiometer comprises positive battery I33, resistance I84, resistance i35 and negative battery I38. As the rotary brush I25 of distributor II9 sweeps over segments 2, 3, 4 and 5 it impresses whatever battery condition is found on the bank terminals of the selector on the bottom winding of relay I8I. When positive battery is connected to the left-hand terminal of the bottom winding of relay I8I, the armature of relay I3I will be actuated to the left. When negative battery is connected to the left-hand terminal of the bottom winding of relay I3I, the armature of relay I3;I will be actuated to the right. v

When the armature of relay I3I engages its left-hand contact I82, a circuit is established from positive battery I83'through resistance I84, contact I82, armature of relay I H, variable resistance I35 and the winding of magnet I38 of the reperforator I31 to negative battery I 38 energizing the winding of the reperforator. When the armature of relay I3I engages contact I89, negative battery I19 is connected through resistance HI and contact I89 to the circuit which extends through the winding of magnet I38. Negative battery is thus connected to both terminals of magnet I38 and the magnet will be deenergized. As the magnet is energized and deenergized, a tape is perforated in one of its five transverse positions or remains unperforated in a well-known manner.

It was pointed out above that the armatures of relays 89 and 91 were locked in position. The manner in which this is performed will now be explained. A circuitmay be traced from the midpoint 9I of the potentiometer associated with relays 89 and 91 through the bottom winding of relay 89, top winding of rela 91, resistance I42, conductor I43, conductor I29, solid ring I28 of distributor H9 and brush I21 to brush I28. As brush I28 engages'segments I to 5 insuccesssion, the circuit will be extended in turn through the corre' sponding selector switch brushes and the particular terminal with which the particular brush is engaged, through the armature of relay 89 or 91, depending upon which of these armatures is connected to the particular bank terminal, to positive or negative battery through contact 98, 99, I 99 or I9I depending upon the particular armature and the articular contact with which the armature is in engagement. The bottom winding of relay 89 and the top winding of relay 91 are arranged so that, in response to the connection of the particular battery with which the armature of either relay is in engagement at the moment, the armature will be maintained in the position which it has assumed during the interval while rotary arm I25 traverses a corresponding segment of distributor H6. If it is assumed, for instance, that the armature of relay 9'! has been actuated to the left to engage contact 96 when rotary arm I25 is in position so that brush I26 engages segment I, the circuit from solid ring I28 will be extended through brush I21, brush I26, segment I, selector arm '5, terminal IIl'Ia of selector bank IIJ'I, armature of relay 91, contact 99 and resistance I09 to positive battery. The effect of current flowing in this path through the top winding of relay 9? will lock, the armature of relay 9'! in engagement with contact 99 during the interval that brush I26 is traversing segment I of distributor IEO. As

brush I26 traverses segment 2, the armature of.,..

relay 9'! which is impressing battery on contact IOBa will be locked in whatever position it has assumed by the effect of current flowing through its top winding. correspondingly, when brush I 23 of distributor III) engages segment 3, the locking circuit for the top winding of relay 9'! is extended through selector brush I I3 and contact Iflfia to the armature of relay 9?. When brush traverses segment 4, the locking circuit for the top winding of relay 9? will be extended through brush H2, terminal I944 of banl: I94 and the armature of relay 9?. Depending upon which position the armature of relay 9! has assumed. positive or negative battery will be supplied to the relay armature, through the locking winding on the same relay, while brush I26 traverses the corresponding segments to lock the armature of 91 in the assumed position. traverses segment 5, the locking circuit is extended through selector brush II I, terminal l lfia of selector bank Ill-'5, armature of relay B9 and through contact 98 or Hit! to positive or negative battery depending upon the position assumed by the armature of relay 89. The armature of relay 89 will be locked in the position which it has assumed by the effect of the current flowing from positive or negative battery through the locking winding of relay 89 while brush I26 traverses segment 5.

It is pointed out that selector brushes I I I to I I5 are arranged to step so as to engage terminals. in corresponding positions on their respective terminal banks simultaneously. The brushes remain battery through contact I 41, contact I48, winding of relay I 45 and resistance I45 to negative battery. The operation of relay I 55 also establishes a circuit from negative battery through resistance I49, contact I58 and the winding of the multibank selector stepping magnet IEI to positive battery energizing the stepping magnet. Switch arms I I I to I I5 of the multibank selectors are stepped one position to engage the next terminal on their respective terminal banks. The direction of rotation is indicated by the arrow. As

the brushes are stepped forward one position, contact I 41 is opened. This opens the locking path of relay I45. Relay I45 releases opening contacts I48 and I50. Rotary brushes III to H5 will remain in engagement with the second terminal When brush 2Z5 on their respective terminal banks for an interval until the symbol for the letter H reappears in the punched tape, when the operation will be repeated and brushes I II, to H5 will he stepped so as to engage their respective third terminals, etc.

Attention is called to the fact that the different terminals on terminal banks I03 to I61 are connected to the armatures of relays 89 and 97 in different manners. This has the effect of further scrambling the signals and prevents their recurrence in any decipherable pattern.

Relay IBI is also provided with a locking circuit. This circuit may be traced from the midpoint I52 of the potentiometer, comprising positive battery I33, resistance I53, resistance I54 and negative battery I35, through resistance I55, top Winding oirelay I3Lto the armature of relay I3! Depending upon which contact the armature of relay IiiI engages, the locking circuit will extend either through contact I62 and resistance I64 to positive battery I63 or through contact I59 and resistance III to negative battery I'iil.

Attention is directed to the fact that the conducting segments on distributor I I0 are separated by insulating gaps. The conducting segments of distributor I I0 subtend smaller radial angles than is usually the case in a distributor arranged for the transmission of five-element permutation code telegraph signals. The insulating gaps separating the conducting segments are considerably longer than usual. It was shown above that the armatures of relays 89 and I'I'I are locked in position during the interval While brush I26 of distributor I I9 is sweeping over a particular conducting segment. Since the armature of each of these relays is looked during this interval, time must be allowed to permit each of these armatures to assume a new position in response to a battery pulse of a different polarity if supplied from distributors 43 or 44. For this reason, the insulating gaps separating the conducting segments of distributor I ID are long enough so that the time required for brush I26 to sweep over each of them is suilicient to permit the armature of relay 8.9 or 9! to assume a new position if required.

It was pointed out also above that the armature of relay I3I was locked in whatever position the armature of relay I3I assumed. While brush I26 is sweeping across a particular conducting segment of distributor I III, the armature of relay ISI will be actuated so as to engage contact I62 or contact I69 depending upon the polarity of the battery sup-plied from the particular conducting segment. As soon as the armature of relay I 31 engages with contact IE2 or contact IE9, the armature of relay I3I is locked in the position it has assumed by the effect of current flowing from. that contact through its top winding. When brush I25 sweeps off a conducting segment, although current is no longer being supplied to the bottom winding of relay I3I through rotary distributor II 6 since brush I26 is in engagement with an insulating segment, the looking circuit through the top winding of relay I3I remains effective to maintain the armature in engagement with the contact determined by the polarity of the battery supplied from the conducting segment last engaged by brush I26. The armature of relay I3I will remain locked in position while brush I26 sweeps over the succeeding insulating segment. When brush I 26 engages the succeeding conducting segment of distributor I I0, current will again be supplied through conductor I 29 to the bottom winding of relay I3I. If the polarity of this current is different from that of the current supplied from the last segment engaged by brush I26, the armature of relay I3I will be operated so as to engage its opposite contact since the effect of the current flowing through the bottom winding is dominant over the effect of the current flowing through the top or looking Winding of relay I3I.

Attention is called to the fact that whereas insulating segments of greater than normal length must be provided on distributor I IE! to permit the armatures of relays 89 and 9'! to respond to the polarity of the current supplied from distributors 43 and 44 during the interval while brush I26 is sweeping over an insulating segment, provision is made to supply a signal impulse of normal duration to the perforator mechanism. This is of longer duration than would be supplied b the shortened conduction agent on the distributor I I acting alone. This is accomplished by means of the locking arrangement for relay I3! described above. Its function, as is doubtless apparent, is to maintain the armature of relay I3! in engagement with the contact it has last engaged during the interval while brush I26 sweeps over the succeeding insulating segment.

Positive and negative battery, respectively, are permanently supplied to the stop and start segments of rotary distributor IIU over obvious circuits. The pulses supplied to the bottom winding of relay I3I as brush I26 sweeps across the stop and start segments are, therefore, not varied. A positive pulse is supplied to the bottom winding of relay I3I by the stop segment of distributor I0, operating the armature of relay I3I so as to engage contact I 62 and supply positive battery invariably to reperforator magnet I36 energizing th magnet for this condition. A negative pulse is supplied to the bottom winding of relay I3I by the start segment of distributor I I0, operating the armature of relay I3I so as to engage contact IE9 and supply negative battery invariabl to the winding of reperforator magnet I36 deenergizing the magnet for this condition.

Attention is called to the fact that the distrib- 1 utors shown are run at different and unrelated speeds to add to the secrecy.

What is claimed is:

1. A mechanism for producing key tape for a permutation code telegraph system comprising 7 a permutation code signal scrambling device, a key tape perforator controlled by said device and means connected to said perforator for changing the setting of said device in response to the pro duction of a single particular permutation code signal combination defining a particular key character in aid perforator, so as to scramble the signal elements comprising the key characters in a different manner, to promote secrecy.

2. A mechanism in accordance with claim 1 which includes a multibank selecting switch having brushes connected in said scrambling device, and means for stepping said brushes to new positions in response to said production of said combination defining said particular key character in said perforator.

3. A mechanism. for producing key tape for a permutation code telegraph system comprising a first and a'second punched tape, a pattern of punched and unpunched areas in each representing a symbol in a multielement permutation signal telegraph code, and means for combining elements forming part of one of said symbols in each tape into a single pattern of punched and unpunched areas in a single key tape to form a single enciphering symbol.

4. A mechanism for producing key tape for a multielement permutation code telegraph system comprising a tape, punched and unpunched areas in said tape representing a permutation code telegraph symbol, a switch, means for operating said switch to generate telegraph signal elements, and means for combining signal elements forming part of said symbol produced by said tape with signal elements produced by said switch to form in a key tape a single enciphering symbol in a permutation telegraph code.

5. In a telegraph system, a telegraph circuit extending from a point on a potentiometer through a winding on each of two polar relays, through a rotary distributor to a plurality of circuits extending through a plurality of switching devices to an armature on each of said relays and opposed contacts on each of said relays connected to batteries of opposite polarities.

6. In a mechanism for producing key tape for a permutation code telegraph system, a first source of permutation code signal elements connected to a first rotary distributor, a second source of permutation code signal'elements connected to a second rotary distributor, a third rotary distributor and means for combining signal elements transmitted from said first and second distributor in said third distributor to form signal elements in the same permutation code for ciphering purposes.

'7. A mechanism in accordance with claim 6 including a signal element scrambling device intermediate the signal element output of one distributor and the Signal element input of another distributor.

8. A mechanism in accordance with claim 6 including a signal element scrambling device intermediate the signal element output of one distributor and the signal element input of another distributor, and means responsive to the production of a particular character by said mechanism for operating said scrambling device to promote secrecy.

9. Inan enciphering system for a permutation code telegraph system, means for producing duplicate enciphering and deciphering key tapes, said means comprising a multibank selector, and means in said producing mean for modifying the settings of said selector in response to the production in said key tapes of a particular symbol by said producing means.

10. A system for producing a key tape for enciphering or deciphering permutation code telegraph signals, a first means for producing multielement permutation code telegraph ignals in said key tape and a second means, comprising a multibank selector, for altering the signals which would normally be generated by said first means in response to the production of a particular multielement permutation code signal in said key tape so as to produce difierent signals in said key tape.

WILMARTH Y. LANG. EDWARD F. WATSON. 

